Source/JavaScriptCore/inspector/agents/InspectorHeapAgent.cpp

   1 /*
   2  * Copyright (C) 2015, 2016 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "InspectorHeapAgent.h"
  28
  29 #include "HeapProfiler.h"
  30 #include "InspectorEnvironment.h"
  31 #include "JSCInlines.h"
  32 #include "VM.h"
  33 #include <wtf/RunLoop.h>
  34 #include <wtf/Stopwatch.h>
  35
  36 using namespace JSC;
  37
  38 namespace Inspector {
  39
  40 InspectorHeapAgent::InspectorHeapAgent(AgentContext& context)
  41     : InspectorAgentBase(ASCIILiteral("Heap"))
  42     , m_frontendDispatcher(std::make_unique<HeapFrontendDispatcher>(context.frontendRouter))
  43     , m_backendDispatcher(HeapBackendDispatcher::create(context.backendDispatcher, this))
  44     , m_environment(context.environment)
  45 {
  46 }
  47
  48 InspectorHeapAgent::~InspectorHeapAgent()
  49 {
  50 }
  51
  52 void InspectorHeapAgent::didCreateFrontendAndBackend(FrontendRouter*, BackendDispatcher*)
  53 {
  54 }
  55
  56 void InspectorHeapAgent::willDestroyFrontendAndBackend(DisconnectReason)
  57 {
  58     ErrorString ignored;
  59     stopTracking(ignored);
  60     disable(ignored);
  61 }
  62
  63 void InspectorHeapAgent::enable(ErrorString&)
  64 {
  65     if (m_enabled)
  66         return;
  67
  68     m_enabled = true;
  69
  70     m_environment.vm().heap.addObserver(this);
  71 }
  72
  73 void InspectorHeapAgent::disable(ErrorString&)
  74 {
  75     if (!m_enabled)
  76         return;
  77
  78     m_enabled = false;
  79
  80     m_environment.vm().heap.removeObserver(this);
  81
  82     clearHeapSnapshots();
  83 }
  84
  85 void InspectorHeapAgent::gc(ErrorString&)
  86 {
  87     VM& vm = m_environment.vm();
  88     JSLockHolder lock(vm);
  89     sanitizeStackForVM(&vm);
  90     vm.heap.collectAllGarbage();
  91 }
  92
  93 void InspectorHeapAgent::snapshot(ErrorString&, double* timestamp, String* snapshotData)
  94 {
  95     VM& vm = m_environment.vm();
  96     JSLockHolder lock(vm);
  97
  98     HeapSnapshotBuilder snapshotBuilder(vm.ensureHeapProfiler());
  99     snapshotBuilder.buildSnapshot();
 100
 101     *timestamp = m_environment.executionStopwatch()->elapsedTime();
 102     *snapshotData = snapshotBuilder.json([&] (const HeapSnapshotNode& node) {
 103         if (Structure* structure = node.cell->structure(vm)) {
 104             if (JSGlobalObject* globalObject = structure->globalObject()) {
 105                 if (!m_environment.canAccessInspectedScriptState(globalObject->globalExec()))
 106                     return false;
 107             }
 108         }
 109         return true;
 110     });
 111 }
 112
 113 void InspectorHeapAgent::startTracking(ErrorString& errorString)
 114 {
 115     if (m_tracking)
 116         return;
 117
 118     m_tracking = true;
 119
 120     double timestamp;
 121     String snapshotData;
 122     snapshot(errorString, &timestamp, &snapshotData);
 123
 124     m_frontendDispatcher->trackingStart(timestamp, snapshotData);
 125 }
 126
 127 void InspectorHeapAgent::stopTracking(ErrorString& errorString)
 128 {
 129     if (!m_tracking)
 130         return;
 131
 132     m_tracking = false;
 133
 134     double timestamp;
 135     String snapshotData;
 136     snapshot(errorString, &timestamp, &snapshotData);
 137
 138     m_frontendDispatcher->trackingComplete(timestamp, snapshotData);
 139 }
 140
 141 static Inspector::Protocol::Heap::GarbageCollection::Type protocolTypeForHeapOperation(HeapOperation operation)
 142 {
 143     switch (operation) {
 144     case FullCollection:
 145         return Inspector::Protocol::Heap::GarbageCollection::Type::Full;
 146     case EdenCollection:
 147         return Inspector::Protocol::Heap::GarbageCollection::Type::Partial;
 148     default:
 149         ASSERT_NOT_REACHED();
 150         return Inspector::Protocol::Heap::GarbageCollection::Type::Full;
 151     }
 152 }
 153
 154 void InspectorHeapAgent::willGarbageCollect()
 155 {
 156     ASSERT(m_enabled);
 157     ASSERT(std::isnan(m_gcStartTime));
 158
 159     m_gcStartTime = m_environment.executionStopwatch()->elapsedTime();
 160 }
 161
 162 void InspectorHeapAgent::didGarbageCollect(HeapOperation operation)
 163 {
 164     ASSERT(m_enabled);
 165     ASSERT(!std::isnan(m_gcStartTime));
 166
 167     // FIXME: Include number of bytes freed by collection.
 168
 169     double startTime = m_gcStartTime;
 170     double endTime = m_environment.executionStopwatch()->elapsedTime();
 171
 172     // Dispatch the event asynchronously because this method may be
 173     // called between collection and sweeping and we don't want to
 174     // create unexpected JavaScript allocations that the Sweeper does
 175     // not expect to encounter. JavaScript allocations could happen
 176     // with WebKitLegacy's in process inspector which shares the same
 177     // VM as the inspected page.
 178
 179     RunLoop::current().dispatch([this, startTime, endTime, operation]() {
 180         auto collection = Inspector::Protocol::Heap::GarbageCollection::create()
 181             .setType(protocolTypeForHeapOperation(operation))
 182             .setStartTime(startTime)
 183             .setEndTime(endTime)
 184             .release();
 185
 186         m_frontendDispatcher->garbageCollected(WTFMove(collection));
 187     });
 188
 189     m_gcStartTime = NAN;
 190 }
 191
 192 void InspectorHeapAgent::clearHeapSnapshots()
 193 {
 194     if (HeapProfiler* heapProfiler = m_environment.vm().heapProfiler())
 195         heapProfiler->clearSnapshots();
 196 }
 197
 198 } // namespace Inspector